Effect of aflatoxin on immunity in turkeys. II. Reversal of impaired resistance to bacterial infection by passive transfer of plasma.

SUMMARY The manifestation of acquired resistance was impaired in turkey poults vaccinated against Pasteurella multocida infection while receiving a ration containing aflatoxin (0.25 to 0.5 ppm B1 activity). Passive transfer of plasma from immune birds or from normal birds supplemented acquired resistance to a point where the recipients survived challenge exposure; passive transfer of cells from immune birds did not supplement resistance. Ratios of organ weight to body weight and histopathologic appearance demonstrated thymal involution in recipients of aflatoxin.